SOLUTION: The width of a rectangle is 3 less than twice it’s length if the area of the rectangle is 47 cm^2 what is the length of the diagonal

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Question 1198427: The width of a rectangle is 3 less than twice it’s length if the area of the rectangle is 47 cm^2 what is the length of the diagonal
Answer by MathLover1(20850) About Me  (Show Source):
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The width of a rectangle is 3 less than twice it’s length
W=2L-3------eq1

A=+47cm%5E2

A=L%2AW---- substitute W
A=L%2A%282L-3%29
47=2L%5E2-3L
2L%5E2-3L-47=0
using quadratic formula we get

L+=+3%2F4+-+sqrt%28385%29%2F4=-4.16
or
L+=+3%2F4+%2B+sqrt%28385%29%2F4=5.66

We obviously only want the second answer.
go to eq1
W=2%2A5.66-3
W=8.32

diagonal:
d%5E2=5.66%5E2%2B8.32%5E2
d%5E2=101.258
d=sqrt%28101.258%29
d=10.06cm